I disapprove of your decision to turn brake lights into skull eyes, but I’ll defend your right to do it. Within reason, people. Nobody wants to clean your ass off the pavement because they couldn’t see that Halloween decoration blinking across the highway. So we’ve got some tips for doing custom lighting properly.

Think Long And Hard About How Much Safety You Want To Sacrifice For Style

Every state has rules on the books about what you’re allowed to use as brake and directional lights on a motorcycle, but some are “enforced” more than others.

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I once failed an inspection in my home state of Massachusetts because somebody couldn’t find a “DOT” stamp on the stock lens of one of my old Suzuki’s blinkers. So you can imagine my shock when the California Department Of Motor Vehicles simply took my word for it when I assured them my dirt bike was “totally legit, bro.”

But just because you can ride around with whatever excuse for “lights” you want doesn’t mean you should.

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Directional lights and brake lights are some of the most important elements in the tenuous safety shield you have on the road as a motorcyclist. The short story is: You want them to be as visible as possible.

Try LED Bulbs, But Make Sure They’re The Right Ones.

LED replacement bulbs are popping up all over the aftermarket and your local auto parts shop like mushrooms now. But just like every other accessory they’re not all created equal, some are well built and others come apart in your hands.

You’ll know a garbage one when you see it, but basically if you’re replacing an incandescent bulb with an LED “bulb” you want little diodes pointing in all directions, not just a flat plane of lights. Note that this doesn’t apply to LED lights that come with their own housing.

If you go the bulb-replacement only route, research what other people have had good luck with on your favorite forums while narrowing down which “bulb” is going to be best for your application.

Use LED-Specific Housing To Get The Most Out Of Your LEDs

When we experimented with an LED replacement bulb in a car headlight, the main conclusion we drew was that LEDs have higher intensity, but at a lower projection distance.

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LED bulbs and incandescents are going to project light in slightly different directions, meaning the optimal visibility is going to happen when LEDs are nestled into reflectors designed for their projection patterns. An LED using reflectors designed for incandescents is suboptimal.

It’s critical to replace an entire light housing with one designed for LED if the light is something you depend on to see, like a headlight. But you can get away with LEDs in stock housings if the primary objective is “being seen” as with blinkers or brakes.

Look For Details An Aftermarket Light Might Miss

I recently ordered an LED blinker and brake light setup for my Yamaha WR250R from an brand called DRC. They make the “Edge2,” which friends said was a good upgrade from the stock unit.

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That means it’d be a great upgrade from what I had on there; this laughably inadequate pile of circuits that looks like it’s soldered together with stale semen.

But seriously, here’s what the previous owner of my motorcycle left me with:

Even though a strawberry with a Christmas tree bulb stuck in it would have been a better brake light than this botched “upgrade,” something I noticed straight away on my shiny new taillight was that seal between the lens and housing could be improved.

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I didn’t like the idea of dust and water getting all up on my diodes, so I pulled the lenses off and ran a bead of silicone along where the parts meet. After peeling off the excess, I feel a lot better about my new lights being protected from the elements.

Mind Your Power Usage: Too Much Or Too Little

You may have heard that LEDs draw less power than incandescent bulbs. This is correct, and generally good for your electrical system as it lightens the load on things.

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But it can also confuse your bike. LED blinkers that draw less juice than incandescents can make the electrical system think they’re broken, causing them to blink very quickly or not at all. I’ve even heard of someone dropping in LED taillights and LED gauge cluster lights, only to create electrical gremlins like a “dimming speedometer” when you tap the brakes.

Luckily, there’s a fix for that.

You Might Need “Load Equalizers” Or Special Relays

If your blinkers get wonky when you swap them for LEDs, you generally have three choices.

You could leave them be, and have your light swap look half-assed.

You can drop in “load equalizers” which basically add resistance to the blinker-system and make the relay think the LED is using the same amount of power as an incandescent. This involves a pretty easy splice, just cut the power wire for the light then wire them together again with an equalizer in between. Whoever sold you the LEDs can sell you one of these too. If not, shop elsewhere.

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The third and best option is to get an aftermarket flasher relay designed to work with your LEDs. This is as simple as popping a pimple. Squeeze the old relay out, it probably looks like a little black box (consult your manual) and drop the new one in.

Here’s the difference the LED-specific relay made on my WR after I swapped blinkers:

(STOCK RELAY)

(RELAY DESIGNED FOR LEDS)

This relay was about a $10 extra option in the LED package I bought. Totally worth it; makes the end result look at lot more polished.

Be Careful “Piggybacking”

We’ve talked a lot about blinkers and brake lights, but you might want to do some auxiliary fogs or accent lighting too. No shame, you do you.

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The safest way to install those things is to follow the instructions they came with and attach them directly to a battery with a dedicated relay.

But the easiest way to install them is to just tap into the power line for an existing light, say the headlight, splice the power line for your new fogs to that and do the same with the ground wire to the other ground. Do not give in to this wicked temptation.

Your factory lights are fused and rated to run a certain amount of wattage. If you exceed that significantly you’re going to blow said fuse. Not the worst thing, except it means your lights might all shut down and that never happens at a convenient time.

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If we’re talking about a light that was formerly incandescent but swapped for LED, ergo drawing much less power, then piggybacking another LED on that one might be OK. But dedicated relays are always ideal on aux-lights.

A factory service manual will have a wiring diagram and a list of how much power a light is supposed to pull. Use this to figure out which wires run which lights, but make your life easier in the long run by running dedicated lines on aftermarket “extra” lights.

Consider A Strobe-Brake

We all know how a taillight works; it’s lit to alert drivers of your general presence and gets brighter when you hit the brake.

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One of the greatest add-ons to come with an aftermarket brake light is a strobe-brake; basically it gives a few rapid flashes before going solid as you start to slow yourself.

In the case of my DRC brake light, you can “upgrade” to this option (plus a higher constant brightness) for about $80. I decided it was worth it for riding in Los Angeles traffic, and so far I’ve been very pleased with the visibility.

I still think there’s a solid chance somebody’s going to steamroll me into oblivion, but at least the bright blinks make my bike stand out just enough to take some tailgater’s eyes off their text message before rear-ending me.

Test Fit Everything First

Did your new lighting kit come with all the brackets and bolts and washers you’re going to need to install it? Are you sure?

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Lay everything out and line it all up with where it’s meant to go before you dismantle your existing light system. That way if you realize you need to order more parts, you don’t have a half-open bike you can’t ride while you wait.

This will also give you an idea of where to cut the wires from your new light kit. Hopefully they gave you extra, otherwise you’re off to the shop. Don’t make your light wires tight as guitar strings, but you won’t want a whole lot of excess floating around under your plastics either.

I went with about two inches of wiggle room on my WR, which got my wires out of the way but gave me the slack to zip them tight against the frame. You don’t want them dangling around in the open where a stick or rock could take them out.

Use OEM Wiring Connections

Your factory lights probably don’t have a solid wire running directly from the fuse box; there will be a little clip for easy disconnection and replacement.

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When you break a light and swap in another OEM piece, you can just bolt the housing to the bike and plug the connector right in. Unfortunately aftermarket parts are generally made cheaper, which means the manufacturer won’t take the time to pre-trim wire lengths or pre-install plugs.

This leaves you with two options; cut off the “plug” on the battery side and hardwire your new light (quick and dirty) or run your new light wiring into the OEM connector plug (clean and correct).

When I bought my DRC kit for the Yamaha, it came with an option to “include OEM connectors for plug-and-play operation!” Yay! When it came in the mail, they meant they included all the parts for you to build an OEM-style connection. Which would then plug in to the factory wiring. Boo.

Don’t Worry, Crimping Is Easy

Fortunately I learned that hooking wires into these little plugs is remarkably easy. That means it’s well worth your time. The bike’s going to look cleaner, be easier to work on in the future, easier to diagnose if issues come up, and just generally be tidier.

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Don’t be like the previous owner of my Yamaha. He threaded the wires together like you’d tie a ten-year-old’s shoes and as a result the lights didn’t work for jack. Take pride in your work.

Test As You Go

Every time you make a change to your setup, try the button and make sure it works. Don’t worry about disconnecting the battery, if you’re using factory-style plugs like we talked about you’re not going to electrocute yourself.

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I’m serious about every change. Tighten the bolt on a light housing? Try the light. Secure a wire with a zip-tie? Try the light.

The reason for such fastidiousness is twofold–

First, you’d be amazed how easily some aftermarket lights can be upset. Too much pull here, wrong twist there, and they can cut out.

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“Won’t they just break under the vibrations of my motorcycle then? Why would I want such a crappy product on my bike?”

You don’t. And you want to figure that out in the garage, not on the highway.

Second, constant re-assessing of the project slows you down and helps you catch silly installation mistakes before you get too far down the rabbit hole.

Wrap Wires

If you bought a decent set of lights, the wires probably came in some sort of protective loom or a tape-like wrapping. Keep that intact, an extra layer of protection won’t hurt and it looks a lot cleaner. Otherwise this stuff is available at your local auto parts joint, but put it on before you start zip-tying!

Tuck Wires

Be wary of where and how you’re securing the new wires to the bike. It can be easy to forget which holes are used for bolts or attachments when the plastics are in place.

Vibration Test

Make sure you actually look at the lights while the bike is running and riding before you declare victory over this project. Obviously. But hey, it can be exciting to be finished! Just keep checking your setup for the first few miles, try to hit some light bumps, and maybe bring your tools in a bag for the first couple rides.

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I like to do that any time I do a modification, because I rarely get it right the first time. That’s why I learn so many great tips to pass to you guys!

Have Any More Tips?

Every setup is going to be a little different, but these are the basic principles I learned tearing down somebody’s terrible aftermarket wiring job and replacing it with something I call quality.

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Let us know if you’ve picked up any other tips on this process, or found pitfalls to avoid. And happy splicing!

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Images via the author, Amazon, Yuri Levchenko/Flickr


Contact the author at andrew@jalopnik.com.